Sleeve and method of connecting a wire to same



Feb. 10,1942. c. H. KLEIN 2,272,244

SLEEVE AND METHOD OF CONNECTING A WIRE T0 SAME Filed Jan. 4. 1940 5a 6 fie. Z

INV ENT OR.

BY 4 [liar/es h. K/m

'Jm w w.

ATTORNEY.

Patented Feb. 10, 1942 UNITED STA'l SLEEVE AND METHOD OF CONNECTING A WIRE TO SAME Charles H. Klein, Cleveland, Ohio, assignor to The National Telephone Supply Company Application January 4, 1940, Serial No. 312,387

4 Claims.

My invention relates to sleeves for joining a wire thereto and more particularly to compression type sleeves for joining an electrical conductor thereto without reducing' the breaking strength of the conductor and without decreasing the electrical conductivity of the joint by the 'use of an'abrasivebeween the sleeve and the wire to be joined.

An object of my invention is to provide a joint between an electrical conductor wire and a sleeve which requires no abrasive to prevent the wire from pulling out of the sleeve when a force is put on the wire with respect tov the sleeve.

Still another object of my invention is to anchor a wire in a sleeve by a combination of frictional engagement and necking engagement.

Another object of my invention is to provide a constant movement clamping tool which is adapted to squeeze a sleeve both into' frictional engagement with a wire and into necking engagement with the wire,

Still another object of my invention is to provide a tool which will clamp a first portion of a sleeve into frictional engagement with a wire to establish a grip between the sleeve and the wire to transfer a portion of the wires load to the sleeve, and which will clamp a second portion of the sleeve into a necking engagement with the wire to transfer a second portion of the wires load to the sleeve, and to so construct the sleeve and the tool that the percent reduction in the total cross-sectional area of the wire caused by the necking engagement of the sleeve will be substantially proportional to the percent reduction in the total load caused by the frictional engagement.

A further object of myrinvention is to provide an improved joint between a sleeve and a wire in which the sleeve necks into the wire at spaced points and at progressivel increased depths to provide a plurality of increasing load resistant grips, and to proportion the percent reduction in the total cross-sectional area of the wire caused by one of the succeeding necking engagements to be substantiallyproportional to the percent reduction in the total load which the previous necking engagements of lesser depth take up.

Another object of my invention is to provide a round sleeve having a hole of substantially constant diameter and having a plurality'of different sized outside diameters which can be squeezed by a constant movement tool to engage a wire at stant diameter therethrough and having a gradually changing outside diameter.

Another object of my invention is to make a joint between a sleeve and a wire by progressively compressing the sleeve and causing the reduction in the cross-sectional area of the wire resulting from the compression to be substantially proportitonal to the load taken up by the preceding wire and a half-portion of the sleeve shown in t Figure 1 after the sleeve has been squeezed at three spaced points by the tool shown in Figure 2.

Figure 4 is a modified form of my sleeve shown in longitudinal cross-section and comprises generally a plurality of sections which have different sized outside diameters.

Figure 5. is a cross-sectional view Of my modified sleeve shown in Figure 4 after each of the sections has been squeezed by a constant movement clamping tool.

Figure 6 shows another modified form of rry invention; and

Figure '7 is a crcss-sectional view of my modifled sleeve shown in Figure 6 after a constant movement clamping tool has squeezed it at three spaced points.

My invention comprises an improved compression sleeve l I for attaching a wire [0 therein and an improved method for securing the wire into the improved compression sleeve I I. As shown in the drawing, the wire may be freely inserted into the longitudinal opening of the sleeve until it abuts against the internal stop substantially midway of the sleeve.

It is known to these versed in the art of splicing electrical conductor wires that a wire l0 may be securely held in the sleeve ll without the use of an abrasive if a compression tool is used to severely squeeze the sleeve II and cause it to neck into the 'wire 10. fNecking means that the compressed portion of the sleeve ll reduces the cross-sectional area of the wire and estab-' lishes a shoulder against which the sleeve abuts.

The shoulder prevents slippage between the wire and the sleeve. on the other hand, the reduction in the crosssectional area of the wire weakens the wire so that it'is apt to fail when an excessive load is put on the wire with respect to the sleeve. A further objection to necking" is the fact that it cold-works the wire and vibrational fatigue is apt to cause an early failure. Figure 1 illustrates my sleeve I I with the wires I inserted therein before it has been squeezed to neck the wire I0.

My device and method is adapted to secure the wire I0 in the sleeve II without an abrasive by necking" the wire III without establishing a weakened cross-sectional area which may fail due to stress or vibrational fatigue.

Figure 3 illustrates in cross-section the lefthalf portion of the sleeve I I shown in Figure 1 after it has been compressed upon the wire II) by means of a tool indicated generally by the reference character I2 and shown in Figure 2. The tool I2 is of the constant movement type and has three clamping areas I4, I5 and I6. Each of the three areas comprises a substantially circular hole in the jaws H of the tool I2. Hole I5 is smaller in diameter than hole I4 and hole I6 is smaller than hole I5. Handles I8 are adapted through a double lever system to open and close the jaws I! of the tool I2. Stops I9 are provided on the handles and adapted to engage each other when the jaws I! of the tool I2 have been closed to a fixed position. Engagement between the stops I9 provides a constant movement to the closing of the jaws I! of the tool.

Figure 3 shows areas A, B, and C which have been squeezed between the jaws I! of the tool I2. Sleeve area A having been squeezed by the clamping area I4, sleeve area B having been squeezed by the clamping area I5 and sleeve area C having been squeezed by the clamping area I6. The diameter of the tool clamping area I4 is designed to cause the tool I2 to squeeze the sleeve II into africtional engagement 20 with the wire I0. Af-necking engagement is prevented by the stops I9 on the handles I8 engaging each other to prevent further squeezing action by the tool I2. The diameter of the tool clamping area I5 is designed to cause the tool I'2 to squeeze the sleeve II into a slight necking engagement 2I with the wire III. The necking engagement is not deep, that is,'the sleeve II does not ma-,

terially depress the wire III, as the stops I9 engage each other and prevent an excess squeezing action. The diameter of the tool clamping area I6 is designed to cause the tool I2 to squeeze the sleeve II into a "necking engagement 22 which is deeper than the preceding "necking engagement 2|.

The frictional engagement 20 is adapted to withstand part of the pull on the wire I0 with respect to the sleeve II. The necking engagements 2| and 22 are adapted to withstand the remainder of the pull between the wire I0 and the sleeve II'. The depth to which the "necking engagements 2I and 22 penetrate the wire I0 is carefully controlled to prevent too great a reduction in the cross-sectional area of the wire I0. Too great a reduction in the cross-sectional area increases the stress in pounds per square inch to a point where failure might occur. The ratio of reduction in the cross-sectional area of the wire III at the neck 2I to the total cross-sectional area of the wire shall not exceed the ratio of the load withstood by the frictional engagement 20 to the total load on the wire III. In

other words, the percentage of reduction in the cross-sectional area of the wire at the "neck" engagement 2I is substantially proportional to the percentage of load taken up by the frictional engagement 20. By so designing the size of the.

clamping holes I4, and I5 in the tool I2 the above ratios may be established. The neck 22 .is also designed to prevent too great a reduction in the cross-sectional area of the wire I 0. The percentage reduction at "neck 22 is substantially proportional to the percentage of load taken up by the frictional engagement 20 and the necking engagement 2I. By proportioning the frictional engagement 20 and the necking" engagements 2| and 22 with respect to the load between the wire III and the sleeve II and with respect to the cross-sectional area of the wire I0 I can establish a joint between the wire I0 and the sleeve II which will not break or slide and which does not use an abrasive which is expensive and may reduce the conductivity of the joint.

Figure 4 is another embodiment of my sleeve II and is adapted-to be used with a constant movement clamping tool having a fixed clamping area in its jaws. Figure 4 illustrates a sleeve having steps 23, 24, and 25. The diameter of the sleeve II at the step 23 is smaller than the diameter of .the sleeve at the steps 24 and 25,

and the diameter of the sleeve at the step 24 is smaller than the diameter at the step 25. Figure 5 shows the stepped sleeve II after a constant movement tool having a fixed squeezing diameter hole has squeezed the sleeve substantially in the center of each of the steps 23, 24 and 25 to form the frictional engagement .20 and the necking engagements 2I and 22. The necking engagements 2I and 22 are formed because of the increased diameters of the steps 24 and 25 over the diameter of the sleeve at the step 23.

Figures 6 and 7 illustrate another sleeve which is adapted to be used with a constant movement clamping tool having a fixed squeezing diameter hole. The diameter of the sleeve increases from the end portion 26 toward the center portion 21. Figure 7 shows the sleeve II after the constant movement clamping tool has squeezed it at three spaced points to form the frictional engagement 20 and the necking" engagements 2I and 22. As in the stepped embodiment the necking engagements are caused by the increased diameters at the points 2I and 22 on the sleeve over the diameter at 20.

In all three embodiments of my invention, I provide for making a joint between a sleeve and a wire by progressively compressing the sleeve and pausing the reduction in the cross-sectional area of the wire resulting from the compression to be substantially proportional to the load taken up by the preceding compressions.

Although I have described my invention with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example and that numerous changes in the details of construction may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

I claim as my invention:

1. The method of fastening the end of a wire to withstand a pulling force from a certain direction which comprises providing a hollow metal sleeve with an end portion, inserting the end of the wire into the sleeve, squeezing the end portion of the sleeve nearest the direction from which the force comes upon the wire to establish a frictional engagement therebetween which is capable of withstanding a portion of the pull on the wire with respect to the sleeve, squeezing another portion of the sleeve upon the wire to establish a necking engagement therebetween which is capable of withstanding the remainder of the pull on the wire with respect to the sleeve.

2. The method of fastening the end of a wire to withstand a pulling force which comprises providing a hollow metal sleeve with an end portion, inserting the end of the wire into the sleeve, squeezing the end portion of the sleeve into a frictional, engagement with the wire which is capable of withstanding a portion of the pull on. the wire with respect tothe sleeve, squeezing another portion of the sleeve upon the wire to establish a "necking engagement therebetween which reduces the cross-sectional area of the wire to an extent that the percentage reduction in cross-sectional area is substantially proportional to the percentage-of the load taken up by the frictional engagement.

3. The method of fastening a wire in a sleeve comprising the steps of inserting the end of the wire in the sleeve, successively compressing the sleeve upon the wire with progressive engagements ranging from a frictional engagement to a necking engagement.

4. The method of fastening the end of a wire to withstand a pulling force which comprises providing a hollow sleeve with an end portion, inserting the end of the wire into the sleeve, squeezing the end portion of the sleeve into a first engagement with the wire which is capable of withstanding a portion of the pull on the wire with respect to the sleeve, squeezing another portion of the sleeve upon the wire to establish a second engagement which necks into the said wire and reduces the cross-sectional area of the wire to an extent that the percentage reduction in cross-sectional area is substantially proportional to the percentage of the load taken up by the said first engagement.

CHARLES H. KLEIN. 

